Motorized pedal power vehicles consist of an attached motor and a transmission that is used to either power the vehicle unassisted, or to assist with pedaling. An example of a motorized pedal power vehicle is a motorized bicycle. Motorized bicycles have been gaining increasing attention in North America, Asia, Europe and elsewhere throughout the world. Advantages include lower energy costs; reduction in other costs such as insurance, licenses, registration, parking; improved traffic flow; environmental friendliness; as well as various health benefits for the user.
Different types of motors and power sources can power motorized pedal power vehicles. Common power sources include internal combustion engines fuelled by gasoline and/or diesel, steam engines, air engines, as well as electric motors. These power sources may be directly connected to an output shaft or geared to adjust the output speed and torque. Power can be applied to a drive wheel using different methods: (1) The front or rear wheel may be powered directly by a power source built into the hub, wheel or rim. (2) A power source mounted within the vehicle's frame may drive the rear wheel via a mechanical power transmission system such as via “chain drives” (i.e. a sprocket with a chain), “belt drives” (e.g. a rubber belt), or “shaft drives” (i.e. directly coupled with a rigid shaft). (3) Power may be transferred to a wheel from a motor mounted directly above, by bringing a powered roller or rubber belt into contact with the wheel or tire.
Commercially, motorized pedal power vehicles are marketed either as complete designs or as add-on motor kits for use on unpowered vehicles. Lighter and more powerful batteries enable electric motors to be more commonly used in motorized pedal power vehicles. As well, such technologies have proven useful for people with physical disabilities and/or restricted mobility such as arthritis and knee injuries.
Companies manufacture internal combustion engine motor conversion kits for conventional bicycles. Examples include: (i) rear-engine, rack-mounted kits using a belt to drive the rear wheel; (ii) rack-mounted, chain-driven, geared transmission; as well as (iii) rack-mounts with either a tire roller-mount or a chain-driven, geared transmission.
Motorized bicycles using electric motors use batteries that are limited in capacity and range, thus pedaling is used to assist in propulsion. Such electric motor bicycle designs are increasingly popular, particularly in countries with heavy traffic congestion, aging populations and fuel shortages.
U.S. Pat. No. 3,921,467 to Matsuura describes a bicycle with a drive train located in the center of the cycle body that consists of a primary sprocket and final sprocket with a tensioner sprocket in between. Adding a secondary sprocket between the primary and final sprockets can modify the gear ratios of the drive train.
U.S. Pat. No. 6,352,131 to Lin describes a unidirectional rotating assembly that allows a chain-ring to rotate while the crank and axle remains still. This design enables the bike to be propelled while the crank is stationary and allows the users to still be able to shift gears.
U.S. Pat. No. 7,314,109 to Holland describes an electrically powered bicycle that includes a hub motor that is mounted to the bicycle frame by its axle. When the bicycle is coasting, the design will enable the rear wheel to drive the motor to provide downhill, regenerative braking capability. U.S. Pat. No. 7,461,714 to Holland also describes a frame-mounted motor that is connected to pedals and to a rear driven wheel through an intermediate jackshaft. A freewheel within this design can recharge batteries during braking or while coasting downhill.
US Patent Application Pub. No. 2010/0307851 to Lin further describes a power-assist system for a bicycle comprising of three components: a motor, a speed-reduction section, and a power-assist section. Such systems operate in four modes: (1) power-assist pedaling mode; (2) pedal only mode; (3) power-assist only mode; and (4) coasting no-power mode.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.